re: companionway hatch for a boat

If none of shipwrights woods are available, you might consider juniper, it’s legendary wrotting resistance. It’s similar in grain and knots to spruce. It is a softwood that is harder than most. I only suggest it as I have used it on a sailboat before for an interior remodel. It’s benefit is coat, relatively cheap. If water ever did get at it like the old doors wrotting would not happen.